1. Field of the Invention
Embodiments described herein are directed to bi-directional streaming of telephony data to a host processor via a standard personal computer interface. Specifically, Pulse Code Modulation (“PCM”) and Time Division Multiplexing (“TDM”) data is moved via a hard disk drive Intelligent Drive Electronics (“IDE”) interface, a hard disk drive Small Computer System Interface (“SCSI”), a Dual In-line Memory Module (“DIMM”) interface, or a Single In-line Memory Module (“SIMM”) interface.
2. Related Art
A typical computer telephony system includes a personal computer (“PC”) and at least one Industry Standard Architecture (“ISA”), Peripheral Component Interconnect (“PCI”), and Compact Peripheral Component Interconnect (“cPCI”) plug-in telephony boards. Such telephony boards include multiple telephone network or phone station interfaces, at least one control processor and associated circuitry, at least one digital signal processor (“DSP”) and associated circuitry for processing voice and tone information, ISA, PCI, and cPCI bus interfaces, and an SCbus, Computer Telephony (“CT”) bus, or Multi-Vendor Integration Protocol (“MVIP”) bus interface to allow sharing of voice data across multiple telephony boards. The SCbus, CTbus and MVIP bus are standardized interfaces in the telephony industry.
As the processing power of host processors continues to increase, there are many leftover million instructions per second (“MIPS”) that are not being used. Making use of the extra MIPS to perform some or all of the functionality of the telephony board's DSPs, thereby eliminating these parts and reducing the cost of the product has become a recent trend.
In current PCs, there are a limited number of slots because most of the circuitry that was once on plug-in boards such as video, sound board, disk drive interfaces, and modems are now integrated into a PC's motherboard. Hence, the number of computer telephony boards that can be placed into a PC is limited by the number of expansion slots that the PC contains.
In order to send the Pulse Code Modulation (“PCM”) and Time Division Multiplexing (“TDM”) voice information from the telephony board to the host processor, a low-latency, high-bandwidth channel is needed. Currently, a special application-specific integrated circuit (“ASIC”) has been designed to reside on a new telephony board. This ASIC can move PCM/ TDM data from the telephony board through the ISA, PCI, or cPCI interface to the host to processor.
While this ASIC solves the problem of delivering the PCMI TDM data streamed to the host processor for newly designed boards, it does not provide a solution for older products or for systems that have all of their expansion slots already filled. A method of moving PCM/TDM data to the host processor on a vehicle other than the ISA, PCI, or cPCI bus interface is thus necessary. Streaming PCM/TDM data via a standard PC interface such as a hard disk drive Intelligent Drive Electronics (“IDE”) interface, a hard disk drive Small Computer System Interface (“SCSI”), a Dual In-line Memory Module (“DNIM”) interface, or a Single In-line Memory Module (“SIMM”) interface will prove beneficial.
That is, a small board that takes PCM/TDM data from the computer telephony board via the SCbus/CTbus/MVIP bus interface and then streams it to the host processor via one of the aforementioned interfaces is advantageous. The board is designed to look like a disk or memory device and have the capability to inform the host processor to initiate, for example, a direct memory access (“DMA”) transfer of the data. Other types of data transfers may similarly be used, such as when data transfer is controlled by the PC's host processor.